Downhole motor sensing assembly and method of using same

ABSTRACT

A downhole sensing assembly for sensing motor parameters of a downhole motor positionable in a wellbore penetrating a subterranean formation is provided. The downhole motor has a stator and a rotor rotatable within the stator. The sensing assembly includes at least one rotor extension operatively connectable to the rotor and movable therewith, at least one marker positionable about the rotor extension, and at least one motor sensor positionable about a downhole tool and operatively coupled to the marker to detect movement of the marker whereby motor parameters, such as rotational speed of the motor, are detectable.

BACKGROUND

This present disclosure relates generally to techniques for performingwellsite operations. More specifically, the present disclosure relatesto techniques, such as drilling motors, for drilling wellbores.

Oilfield operations may be performed to locate and gather valuabledownhole fluids. Oil rigs are positioned at wellsites, and downholeequipment, such as drilling tools, are deployed into the ground by adrill string to reach subsurface reservoirs. At the surface, an oil rigis provided to deploy stands of pipe into the wellbore to form the drillstring. Various surface equipment, such as a top drive, or a Kelly and arotating table, may be used to apply torque to the stands of pipe, tothreadedly connect the stands of pipe together, and to rotate the drillbit. A drill bit is mounted on the lower end of the drill string, andadvanced into the earth by the surface equipment to form a wellbore.

The drill string may be provided with various downhole components, suchas a bottom hole assembly (BHA), drilling motor, measurement whiledrilling, logging while drilling, telemetry and other downhole tools, toperform various downhole operations. The drilling motor may be providedto drive the drill bit and advance the drill bit into the earth.Examples of drilling motors are provided in U.S. Pat. Nos. 7,419,018,7,461,706, 6,439,318, 6,431,294, 2007/0181340, and 2011/0031020, theentire contents of which are hereby incorporated by reference herein.

SUMMARY

In at least one aspect, the disclosure relates to a downhole sensingassembly for sensing motor parameters of a downhole motor positionablein a wellbore penetrating a subterranean formation. The downhole motorhas a stator and a rotor rotatable within the stator. The rotorextension is operatively connectable to the rotor and movable therewith.The marker is positionable about the at least one rotor extension. Themotor sensor is positionable about the downhole tool and operativelycoupled to the at least one marker to detect movement of the at leastone marker whereby motor parameters comprising rotational speed of themotor are detectable.

At least one of the rotor extension, the marker and the motor sensor arepositioned outside of the downhole motor. The marker is integral withthe rotor extension. The marker is operatively connectable to the rotorextension. The rotor extension includes a rotor catch. The rotorextension includes a rod threadedly connectable to an end of the rotor.The rotor extension extends from an uphole end of the rotor. The rotorextension extends from the rotor and into a sub adjacent to the motor.The rotor extension includes a handle with a plurality of membersextending therefrom. The members are integral with the marker. Themarker is integral with the rotor extension. The marker is operativelyconnectable to the rotor extension.

The rotor extension includes an integral or a modular body. The rotorincludes an upper portion and a lower portion threadly connectable tothe rotor. The marker is positionable about the lower portion. Themarker includes a magnet generating a magnetic field detectable by thesensor. The motor sensor includes at least one of a magnetic,electromagnetic, proximity, optical, electro-magnetic, acoustic,fluxgate, magneto-resistive, magnetometer, and Hall Effect sensor. Thedownhole sensing assembly may also include at least one downhole sensorcomprising at least one of a temperature, pressure, vibration, force,and gyroscope sensor.

In another aspect, the disclosure relates to a drilling system fordrilling a wellbore in a subterranean formation. The drilling systemincludes a downhole motor positionable in a downhole drilling tooldisposable in the wellbore (the downhole motor includes a stator and arotor), and a downhole sensing assembly. The downhole sensing assemblyincludes at least one rotor extension operatively connectable to therotor and movable therewith, at least one marker positionable about therotor extension, and at least one motor sensor positionable about thedownhole tool and operatively coupled to the one marker to detectmovement of the marker whereby motor parameters comprising rotationalspeed of the motor are detectable.

The drilling system may also include a surface unit and/or a downholeunit operatively connected to the downhole sensing assembly, telemetryoperatively coupling the surface unit and the downhole sensing assembly,and/or a top sub operatively connected to the downhole motor. The rotorextension, the marker and/or the at least one motor sensor may bepositioned in the top sub.

Finally, in another aspect, the disclosure relates to a method ofsensing parameters of a motor of a downhole tool positionable in awellbore penetrating a subterranean formation. The motor includes astator and a rotor. The method involves providing the motor with adownhole sensing assembly. The downhole sensing assembly includes atleast one rotor extension operatively connectable to the rotor andmovable therewith, at least one marker positionable about the rotorextension, and at least one motor sensor positionable about the downholetool and operatively coupled to the marker to detect movement of themarker. The method further involves detecting the at least one markerwith the at least one marker sensor, determining downhole parameterscomprising revolutions per minute of the motor based on the detecting,and determining downhole parameters with at least one downhole sensor.The method may also involve selectively adjusting drilling based on atleast one of drilling parameters determined from the detecting, downholeparameters determined with the at least one downhole sensor, and knownparameters.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the above recited features and advantages of the presentdisclosure can be understood in detail, a more particular description ofthe invention, briefly summarized above, may be had by reference to theembodiments thereof that are illustrated in the appended drawings. It isto be noted, however, that the appended drawings illustrate only typicalembodiments and are, therefore, not to be considered limiting of itsscope. The Figures are not necessarily to scale and certain features,and certain views of the Figures may be shown exaggerated in scale or inschematic in the interest of clarity and conciseness.

FIG. 1 depicts a schematic view, partially in cross-section of adownhole drilling tool deployed into a wellbore, the downhole drillingtool having a drilling motor with a motor sensing assembly.

FIG. 2 depicts a cross-sectional view of a portion of the downholedrilling assembly depicting the drilling motor and motor sensingassembly.

FIGS. 3A-3C depict cross-sectional, end and perspective views of a motorsensing assembly.

FIGS. 4A-4C depict cross-sectional, end and perspective views of anothermotor sensing assembly.

FIG. 5 depicts a flow chart of a method of sensing parameters of amotor.

DETAILED DESCRIPTION OF THE INVENTION

The description that follows includes exemplary apparatus, methods,techniques, and/or instruction sequences that embody techniques of thepresent subject matter. However, it is understood that the describedembodiments may be practiced without these specific details.

The present disclosure relates to a motor sensing assembly usable forsensing parameters, such as rotation, of a motor in a downhole tool. Themotor sensing assembly may include a rotor extension (e.g., a rotorcatch) coupled to a rotor of the motor, a marker positionable about therotor extension, and a motor sensor coupled to a fixed portion of thedownhole tool. The motor sensor may be used to detect changes inmagnetic fields caused by rotation of the rotor. The marker may bedetectable by the motor sensor to provide, for example, rotational speedof the drilling motor (e.g., revolutions per minute (RPMs) of a statorrelative to a rotor of the drilling motor) and/or movement of the rotor(e.g., wobble or whirl).

The motor sensing assembly may be positioned outside of the motor andisolated from motion and/or vibration therein. The rotor extension mayextend from the rotor and/or motor to facilitate access to the rotorand/or to provide measurements therefrom. The motor sensor may bepositioned outside the drilling motor and in a non-rotating portion ofthe downhole tool to facilitate access to components of the assembly,transfer of measurement, and/or collection of data. The motor sensingassembly may be used for measurement of bit RPM through the motor. Themeasurements may be used for detection of bit stick/slip, motorperformance, and mechanical specific energy (MSE), as well as otherinfo.

FIG. 1 depicts an example environment in which a downhole motor with amotor sensing assembly may be used. While a land-based drilling rig witha specific configuration is depicted, the motor sensing assembly may beusable with a variety of land based or offshore applications. In eachversion, a drilling system 100 includes a rig 101 positionable at awellsite 102 for performing various wellbore operations, such asdrilling.

FIG. 1 depicts a schematic view, partially in cross-section, of thewellsite 102. The drilling system 100 also includes a drill string 103with a downhole tool (or bottom hole assembly (BHA)) 108 and a drill bit104 at an end thereof. The drill string 103 may include drill pipe,drill collars, coiled tubing or other tubing used in drillingoperations. The drill bit 104 is advanced into a subterranean formation105 to form a wellbore 106.

Various surface (or rig) equipment 107, such as a Kelly, rotary table,top drive, elevator, etc., may be provided at the rig 101 to rotate thedrill bit 104. A surface unit 112 a is also provided at the surface tooperate the drilling system. Downhole equipment, such as the downholetool 108, is deployed from the surface equipment 107 and into thewellbore 106 by the drill string 103 to perform downhole operations.

The downhole tool 108 is at a lower end of the drill string 103 andcontains various downhole equipment for performing downhole operations.Such equipment may include, for example, measurement while drilling,logging while drilling, telemetry, processors and/or other downholetools. As shown, the downhole tool 108 includes a downhole unit 112 bfor communication between the downhole tool 108 and the surface unit 112a. One or more units 112 a,b may be provided.

The downhole tool 108 may also be provided with various devices, such asmotor 111 for operating downhole equipment, such as the drill bit 104.The downhole tool 108 may be provided with one or more motors 111 forrotating the drill bit 104. As shown, a single motor 111 is positionedbetween the drill string 103 and the drill bit 104. The motor 111 may beused to convert hydraulic energy from the mud passing therethrough intorotational energy. The rotational energy may be used to power and/ordrive components of the downhole tool 108.

The motor 111 may be any motor with moving parts, such as a moineaumotor including a helical rotor 124 rotationally positionable in ahelical stator 122 and driven by the flow of mud therethrough. Thehelical stator 122 may have a number of lobes along an inner surface.The helical rotor 124 may have a number of lobes along a cross-sectionof an outer surface thereof, with the number of rotor lobes being lessthan the number of stator lobes. An example of a moineau motor that maybe usable is provided in U.S. Pat. No. 7,419,018 previously incorporatedby reference herein. The motor 111 may be capable of providing rotationto the bit 104.

The rotor 124 may be attached to a bottom of the motor 111 and allowedto spin relative to a top portion of the motor 111. The top portion ofthe motor 111 may be attached to a top sub 126. The top sub 126 mayperform a secondary function of retaining the rotor 124 in case of sometype of failure. The motor 111 may be provided with a downhole sensingassembly 119 for detecting downhole parameters, such as rotation of therotor, as will be described more fully herein.

A mud pit 110 may be provided at the surface for passing mud through thedrill string 103, the downhole tool 108 and out the bit 104 as indicatedby the arrows. The motor 111 may be activated by fluid flow from the mudpit 110 and through the drill string 103. Flow of mud from pit 110 maybe used to activate the motor 111 during drilling, for example byrotationally driving the motor 111 and/or other downhole components.Pressurized mud flowing through the motor 111 may be used to increaserelative RPM from the stator 122 to the rotor 124.

FIG. 2 depicts a portion of the downhole tool 108 of FIG. 1 with adownhole sensing assembly 219 operatively connected to the motor 111. Asshown in this view, the motor 111 includes a drill collar 220 with ahelical stator 222 and helical rotor 224 therein. The top sub 126includes a drill collar 228 operatively connected to the drill collar220 of the motor 111 uphole therefrom.

The downhole sensing assembly 219 includes a rotor extension 230, amarker 232, a motor sensor 234, and units 112 a,b. The rotor extension230 is operatively connected to the rotor 224. As shown, the rotorextension 230 is connected to an uphole end of the rotor 224, but may beat other locations. As also shown, the rotor extension 230 is positionedin the motor 111, and extends into the sub 126.

As depicted in FIG. 2, the marker 232 and motor sensor 234 arepositioned in the sub 126 outside of the motor 111. The position of thesensing assembly 219 and its components may be selected based on need.For example, the components of the sensing assembly 219 may bepositioned outside the motor 111 to isolate such components frommovement of the motor 111 and/or fluid turbulence passing therethrough.In at least some cases, components of the sensing assembly 219, such asthe rotor extension 230, may be positioned outside the motor 111 toprevent interference with the motor 111. Components of the sensingassembly 219 may also be positioned outside the motor 111 and/or in sub126 where additional space may be provided for accessing the downholesensing assembly 219.

The rotor extension 230 may be any device positionable about the rotor224 and movable therewith for supporting the marker 232. The rotorextension 230 may be, for example, a rotor catch or handle operativelyconnected (e.g., threadedly connected) to the rotor 224. Rotor catchesmay be used, for example, to access and grip the rotor 224 for retrievalfrom the motor 111. The rotor extension 230 may perform other functionsassociated with the motor 111 and/or downhole tool 108, such asfacilitating removal of the rotor 224, affecting movement of the rotor224, extending the rotor 224 outside of the motor 111, among others.

The marker 232 may be positioned on, in or about the rotor extension230. The marker 232 may optionally be a portion of the rotor extension230 itself and/or be formed integrally therewith. The marker 232 ispositioned offset from a central axis A of the rotor 224. The marker 232may be identifiable by the motor sensor 234 for measuring variousdownhole parameters, such as motor parameters of the motor 111.

In an example, the marker 232 may be a magnetic device (such as amagnet, electromagnetic, Hall Effect sensor, etc.) generating a magneticfield M detectable by the motor sensor 234. As the rotor 224 rotatesduring operation, the marker 232 moves with the rotor 224 such that themarker 232 is detectable by the motor sensor 234. The motor sensor 234may be used, for example, to count the number of times the marker 232passes by the motor sensor 234. The frequency with which the magneticfield M changes may be used to calculate, for example, angular rotationrate of the motor 111. This information may be used, for example, toprovide revolutions per minute (RPM) of the rotor 224 and/or torsionalvibration of the motor 111.

The motor sensor 234 is positioned along a fixed location along thedownhole tool 108, such as in the drill collar 228 or the stator 222.The motor sensor 234 may be, for example, removably embedded in thedrill collar 228 with a portion extending therefrom. The motor sensor234 may be positioned for operative coupling with the marker 232. Themotor sensor 234 may also be positioned on a shoulder 236 of the drillcollar 228 of the sub 126. The location of the motor sensor 234 may bein a top, side, and/or bottom portion of the drill collar 228. The motorsensor 234 may be positioned so that the motor sensor 234 monitors anylocation of the marker 232. The motor sensor 234 may also provide otherinformation, such as the location of the motor 111 and/or motor and/ordownhole parameters.

The motor sensor 234 may be any sensor, such as a proximity sensor withmagnetic, electromagnetic, proximity, optical or other capabilities,capable of detecting the marker 224. The motor sensors 234 may include,for example, a sensor that senses a changing magnetic field, such as anelectro-magnetic, acoustic, fluxgate, magneto-resistive, or magnetometer(e.g., Hall Effect) type sensor. For example, the sensor may be amagnetometer (scalar or vector) that may be used to measure a change inmagnetic field strength. The motor sensor 234 may also be a distancesensor, such as electro-magnetic or acoustic sensor, that is designed tomeasure the distance or stand-off of the marker 232 from the motorsensor 234.

Additional sensors, such as downhole sensors S1 and S2 may be providedto measure other downhole parameters, such as temperature, pressure,vibration, forces (e.g., torque, bending force, weight on bit), motordynamics, and other measurements. As shown, downhole sensor S1 ispositioned in the rotor and downhole sensor S2 is positioned in therotor extension 230, and be positioned in any location about motor 111and/or downhole tool 108.

Measurements made by the motor sensor 234 and the downhole sensors S1and S2 may be analyzed to understand performance and operation of themotor 111 and associated equipment. In an example, the downhole sensorsS1 and/or S2 may be a gyroscope to provide an ‘earth reference’ and/orposition in 3D space. The earth reference may be associated with theRPMs of the motor sensor 234. The earth reference and RPMs may beanalyzed to determine, for example, motor stalling, string driven stickslip dynamics, mechanical specific energy (MSE), among others. The earthreference may also be used to differentiate motor stalling and stringdriven stick slip dynamics.

The motor sensor 234 and downhole sensors S1 and S2 may be operativelyconnected to the surface unit 112 a and/or a downhole unit 112 b asschematically depicted. The motor sensing assembly 219 may be wired orwireless coupled to the surface and downhole units 112 a,b forinteraction therewith. Data and/or other signals may be passed betweenthe motor sensor 234 and the surface and/or downhole units 112 a,b. Themotor sensor 234 may be used, for example, to count revolutions of therotor 224 as the marker 232 moves relative to the motor sensor 234. Therevolutions counted may be passed to the surface and/or downhole units112 a,b. The data may be collected and/or analyzed to provide motorparameters, such as RPM, speed of rotation, vibration, pressure, etc.

Based on the data received, various equipment at the wellsite may beselectively activated. For example, based on the RPMs detected by themotor sensors 234, the mud flow through the downhole tool, torqueapplied at the rig, and/or other operating parameters may be selectivelyadjusted. Optimum operational (e.g., drilling) and/or operationalparameters may be determined and/or selected based on the measurementstaken using the sensing assembly 219.

The surface and/or downhole units 112 a,b may be provided with, forexample, a processor (e.g., central processing unit (CPU)), filters,memory, and/or other devices for communicating, collecting, processing,analyzing and/or otherwise using the data collected by one or moresensors. Other communication and/or processing devices, such as atelemetry device (e.g., wired-drill pipe, mud pulse, electro-magnetic,acoustic, and/or inductive coupling), transceivers, and antennas mayalso be coupled to the motor sensor 234. For example, the drill collarsmay be wired for wired telemetry through the drill string such that datamay be passes through the wired telemetry system.

The data taken from the various sensors may be filtered with the filter(e.g., a low-pass, high-pass, or bandpass filter). The filtered data maythen be acquired by an analog-to-digital converter, frequency-counter,or digital input. The acquired data may then be passed to the CPU (e.g.,a microcontroller or other processor). The CPU may use the acquired datato determine an increase in RPM from the top sub 126 of the motor 111 tothe rotor 224 of the motor 111. An increase in rotation rate may besaved to internal or external memory. The increase in rotation rate maybe passed to the surface using telemetry.

The increase in rotation rate may also be combined with additional RPMmeasurements taken at or above the top sub 126 of the motor 111. Addingthese measurements together may result in the total RPM of the rotor 224of the motor 111. Measured RPM of the motor 111 may be combined withother measurements for comparison and/or evaluation. Other measurementsmay be used for further analysis. For example, RPM may also bedetermined at the drill bit (e.g., 104 of FIG. 1) by measuring RPM andrecording the data to memory for comparison and/or analysis with the RPMmeasurements of the rotor extension 230. In another example, bit RPMthrough the motor, MSE, bit stick/slip, and motor performance may bedetermined.

Based on the data received from the sensors and/or other sources, theunits 112 a, b may also be capable of sending signals to operate,activate, adjust, or otherwise control operation of the wellsite. Themotor 111 and/or downhole tool 108 (as well as other wellsitecomponents) may be selectively activated based on control signalsreceived from the units 112 a,b.

As demonstrated by FIGS. 3A-4C, the rotor extension 230 may take variousforms, such as a unitary or modular configuration shaped as desired toachieve the desired function. The rotor extension 230 may be removableand/or replaceable so that various rotor extensions 230 may be tailoredfor use with specific applications.

FIGS. 3A-3C depict various views of an example downhole sensing assembly319 usable with the downhole tool 108 of FIG. 2. FIG. 3A shows thedownhole sensing assembly 319 positioned in the downhole tool 108 aboutthe downhole motor 111. FIG. 3B shows a top view of the downhole sensingassembly 319. FIG. 3C shows a perspective view of a rotor extension 330of the downhole sensing assembly 419. The rotor extension in thisversion may be a rotor extension 330 with a unitary body.

The rotor extension 330 has a rotor end 340 threadedly connected to anuphole end of a rotor 224. The rotor extension 330 has an elongate body342 extending from the rotor end 340 to a flow end 344. A shoulderportion 343 extends radially about the elongate body 342 adjacent therotor end 340.

The rotor extension 330 also has a handle 346 at the flow end 344. Thehandle 346 may be secured to the body 342 by a bolt 345. The handle 346has a generally elliptical shape with radial members 350 extendingtherefrom and with the flow holes 348 for the passage of fluidtherethrough. Flow holes 348 through the handle 346 may allow flowthrough the motor 111 without much flow restriction. The handle 346 maybe in the form of a spinning disk (or hub) with interrupted outerdiameter or a series of the members (or splines) 350 extending from thehandle 346 either above or below a motor end of the top sub 126.

The members 350 of the rotor extension 330 may be modified to increaseresolution and/or accuracy of the measurement. The members 350 may beexpanded to reach further out toward the wall of the drill collar 228 ofthe sub 126. Additional members 350 may be added to rotor extension 330.The members 350 may be individual spokes extending from the hub of thehandle 346. In another example, the members 350 may be contoured lobesextending from a central portion of the handle 346.

Portions of the rotor extension 330, such as members 350, may be used asa marker 332 with or without additional markers 232. In this version,the members 350 may act as the marker 332 detectable by the motor sensor234. The members 350 may be made of a metal (e.g., steel) that changes amagnetic field of the sensor. The members 350 may also have additionalmagnetism added thereon, for example, in a form of a magnet. Theadditional magnetism may be specifically polarized to allow for a northand/or south pole at various specific members 350 in various orders toallow for rotation direction determination. A separate marker (e.g., 232of FIG. 2) may optionally be provided with or without the member 350 asthe marker 332.

The members 350 and/or markers 332, 232 may be positioned above, below,or through a motor end of the top sub 126. The motor sensor 234 may bepositioned facing uphole, downhole, or perpendicular to the centerline Aof the rotor 224 with these members 350 extending off the handle 346.The spinning handle 346 with members 350/markers 332 may take the placeof the extensions or interrupted geometry of the handle 346. Variousembodiments of members 350, markers 332, or other interrupted geometryare possible.

The motor sensor 234 may be capable of detecting the members 350 and/ormarker 232 as they pass adjacent the motor sensor 234 as shown in FIG.3B. The members 350 may be counted to determine rotation of the handle346, and thereby the RPMs of the rotor 224 relative to the stator 222.Motor sensor 234 and units 112 a,b may be provided in the sub 126 aspreviously described.

The motor sensor 234 may be positioned and adjusted to provide a desiredstandoff between the marker 332 and the motor sensor 234. The motorsensor 234 may be positioned in the sub 126 and view the members 350 ofthe handle 346 as they pass by the motor sensor 234.

FIGS. 4A-4C depict various views of an example downhole sensing assembly419 usable with the downhole tool 108 of FIG. 2. FIG. 4A shows thedownhole sensing assembly 419 positioned in the downhole tool 108 aboutthe downhole motor 111 (FIG. 1). FIG. 4B shows a top view of thedownhole sensing assembly 419. FIG. 4C shows a perspective view of arotor extension 430 of the downhole sensing assembly 419. The rotorextension 430 may be a rotor catch with a modular body.

As shown in FIG. 4A, the rotor extension 430 has a rotor end 440threadedly connected to an uphole end of a rotor 224. As shown in FIGS.4A and 4B, the rotor extension 430 has a lower body portion 443 and anupper elongate body portion 445 extending from the rotor end 440 to aflow end 444. The lower body portion 443 has a flanged end 447 extendingradially therefrom.

The upper body portion 445 has a threaded connection end 449 threadedlyconnected to the flanged end 447. The upper body portion 445 also has anelongate body 451 extending from the connection end 449 to the flow end444, and a handle 456 at the flow end 444. The handle 456 may be securedto the body 451 by a bolt 445.

As shown in the top view of FIG. 4B, the flanged end 447 has a generallyelliptical shape with radial members 450 extending therefrom. In thisversion, the flanged end 447 acts as a marker 432. The members 450and/or marker 432 may be similar to the members 350 and/or marker 332 ofFIGS. 3A-3C. Additional markers 232 may also be provided.

The motor sensor 234 is positioned in the drill collar 228 adjacent theflanged end 447. The motor sensor 234 is capable of detecting themembers 450 as they pass adjacent the motor sensor 234 as shown in FIG.4B. The members 450 may be counted to determine rotation of the handle456, and thereby the RPMs of the rotor 224 in the stator 222. Motorsensor 234 and units 112 a,b may be provided in the sub 126 as describedherein.

FIG. 5 is a flow chart depicting a method of sensing parameters of amotor. The motor may be the motor 111 of a downhole tool 108 and havinga rotor and stator as provided herein. The method involves 560—providingthe motor with a downhole sensing assembly. The downhole sensingassembly includes at least one rotor extension operatively connectableto the rotor and movable therewith, at least one marker positionableabout the rotor extension, and at least one marker sensor positionableabout the downhole tool and operatively coupled to the marker. Themethod also involves 562—detecting the marker(s) with the marker sensor(s).

The method may also involve 564—determining downhole parameters (e.g.,revolutions per minute) of the motor based on the detecting,566—determining downhole parameters with at least one downhole sensor,and/or 568—selectively adjusting drilling based on drilling parametersdetermined from the detecting, downhole parameters determined withdownhole sensor, and/or other known parameters. The method may beperformed in any order, and repeated as desired.

It will be appreciated by those skilled in the art that the techniquesdisclosed herein can be implemented for automated/autonomousapplications via software configured with algorithms to perform thedesired functions. These aspects can be implemented by programming oneor more suitable general-purpose computers having appropriate hardware.The programming may be accomplished through the use of one or moreprogram storage devices readable by the processor(s) and encoding one ormore programs of instructions executable by the computer for performingthe operations described herein. The program storage device may take theform of, e.g., one or more floppy disks; a CD ROM or other optical disk;a read-only memory chip (ROM); and other forms of the kind well known inthe art or subsequently developed. The program of instructions may be“object code,” i.e., in binary form that is executable more-or-lessdirectly by the computer; in “source code” that requires compilation orinterpretation before execution; or in some intermediate form such aspartially compiled code. The precise forms of the program storage deviceand of the encoding of instructions are immaterial here. Aspects of theinvention may also be configured to perform the described functions (viaappropriate hardware/software) solely on site and/or remotely controlledvia an extended communication (e.g., wireless, internet, satellite,etc.) network.

While the embodiments are described with reference to variousimplementations and exploitations, it will be understood that theseembodiments are illustrative and that the scope of the inventive subjectmatter is not limited to them. Many variations, modifications, additionsand improvements are possible. For example, one or more motor sensingassemblies, motor sensors, markers, members, and/or other featuresprovided herein may be utilized about the motor and/or downhole tool.

Plural instances may be provided for components, operations orstructures described herein as a single instance. In general, structuresand functionality presented as separate components in the exemplaryconfigurations may be implemented as a combined structure or component.Similarly, structures and functionality presented as a single componentmay be implemented as separate components. These and other variations,modifications, additions, and improvements may fall within the scope ofthe inventive subject matter.

1. A downhole sensing assembly for sensing motor parameters of adownhole motor positionable in a wellbore penetrating a subterraneanformation, the downhole motor having a stator and a rotor rotatablewithin the stator, comprising: at least one rotor extension operativelyconnectable to the rotor and movable therewith; at least one markerpositionable about the at least one rotor extension; and at least onemotor sensor positionable about a downhole tool and operatively coupledto the at least one marker to detect movement of the at least one markerwhereby motor parameters comprising rotational speed of the downholemotor are detectable.
 2. The downhole sensing assembly of claim 1,wherein at least one of the rotor extension, the at least one marker andthe at least one motor sensor is positioned outside of the downholemotor.
 3. The downhole sensing assembly of claim 1, wherein the at leastone marker is integral with the at least one rotor extension.
 4. Thedownhole sensing assembly of claim 1, wherein the at least one marker isoperatively connectable to the at least one rotor extension.
 5. Thedownhole sensing assembly of claim 1, wherein the at least one rotorextension comprises a rotor catch.
 6. The downhole sensing assembly ofclaim 1, wherein the at least one rotor extension comprises a rodthreadedly connectable to an end of the rotor.
 7. The downhole sensingassembly of claim 1, wherein the at least one rotor extension extendsfrom an uphole end of the rotor.
 8. The downhole sensing assembly ofclaim 1, wherein the at least one rotor extension extends from the rotorand into a sub adjacent to the downhole motor.
 9. The downhole sensingassembly of claim 1, wherein the at least one rotor extension comprisesa handle with a plurality of members extending therefrom, the pluralityof members integral with the at least one marker.
 10. The downholesensing assembly of claim 1, wherein the at least one marker is integralwith the at least one rotor extension.
 11. The downhole sensing assemblyof claim 1, wherein the at least one marker is operatively connectableto the at least one rotor extension.
 12. The downhole sensing assemblyof claim 1, wherein the at least one rotor extension comprises one of anintegral and a modular body.
 13. The downhole sensing assembly of claim1, wherein the at least one rotor comprises an upper portion and a lowerportion threadly connectable to the at least one rotor, the at least onemarker positionable about the lower portion.
 14. The downhole sensingassembly of claim 1, wherein the at least one marker comprises a magnetgenerating a magnetic field detectable by the at least one motor sensor.15. The downhole sensing assembly of claim 1, wherein the at least onemotor sensor comprises at least one of a magnetic, electromagnetic,proximity, optical, electro-magnetic, acoustic, fluxgate,magneto-resistive, magnetometer, and Hall Effect sensor.
 16. Thedownhole sensing assembly of claim 1, further comprising at least onedownhole sensor comprising at least one of a temperature, pressure,vibration, force, and gyroscope sensor.
 17. A drilling system fordrilling a wellbore in a subterranean formation, the drilling systemcomprising: a downhole motor positionable in a downhole drilling tooldisposable in the wellbore, the downhole motor comprising a stator and arotor; a downhole sensing assembly, comprising: at least one rotorextension operatively connectable to the rotor and movable therewith; atleast one marker positionable about the at least one rotor extension;and at least one motor sensor positionable about the downhole drillingtool and operatively coupled to the at least one marker to detectmovement of the at least one marker whereby motor parameters comprisingrotational speed of the downhole motor are detectable.
 18. The drillingsystem of claim 17, further comprising at least one of a surface unitand a downhole unit operatively connected to the downhole sensingassembly.
 19. The drilling system of claim 17, further comprisingtelemetry operatively coupling the surface unit and the downhole sensingassembly.
 20. The drilling system of claim 17, further comprising a topsub operatively connected to the downhole motor, and wherein at leastone of the at least one rotor extension, the at least one marker and theat least one motor sensor are positioned in the top sub.
 21. A method ofsensing parameters of a motor of a downhole tool positionable in awellbore penetrating a subterranean formation, the motor comprising astator and a rotor, the method comprising: providing the motor with adownhole sensing assembly, the downhole sensing assembly comprising: atleast one rotor extension operatively connectable to the rotor andmovable therewith; at least one marker positionable about the at leastone rotor extension; and at least one motor sensor positionable aboutthe downhole tool and operatively coupled to the at least one marker todetect movement of the at least one marker; detecting the at least onemarker with the at least one marker sensor.
 22. The method of claim 21,further comprising determining downhole parameters comprisingrevolutions per minute of the motor based on the detecting.
 23. Themethod of claim 21, further comprising determining downhole parameterswith at least one downhole sensor.
 24. The method of claim 21, furthercomprising selectively adjusting drilling based on at least one ofdrilling parameters determined from the detecting, downhole parametersdetermined with the at least one downhole sensor, and known parameters.25. The downhole assembly of claim 1, wherein the at least one markercomprises a magnet, and wherein the at least one rotor extensioncomprises a rotor catch, the at least one magnet positionable in therotor catch.